Improved Coating Adhesion Test Method for Rotary Cement Kilns

摘要

In rotary cement kilns, the performance of refractory bricks depends largely on the formation of a cement coating on the hot face. A coating adhesion test was conducted by using a rotary slag testing apparatus with an automatic slag feeder and drainer. As a result, the coated specimens with a similar texture to actually used bricks were experimentally reproduced. Microstructure observation revealed that spinel grains of magnesia-spinel brick easily react with cement clinkers to form liquid phase, which infiltrates into the brick matrix to enhance coating adhesion through an anchor effect. However, infiltration of excess amount of liquid phase, derived from not only the spinel decomposition but also partial melting of cement clinker, can cause brick erosion at high temperature.